Medical Implants Research Articles

Surface hydrophilicity promotes bacterial twitching motility.

The bacterial type IV pilus (T4P) is a critical virulence factor for many medically important pathogens, some of which are prioritized by the World Health Organization for their high levels of antibiotic resistance. The T4P is known to propel bacterial twitching motility, the analysis of which provides a convenient assay for T4P functionality. Here, we show that bile salts and other detergents augment the twitching of multiple bacterial pathogens. We identified the underlying mechanism as the alteration of surface hydrophilicity by detergents. Consequently, hydrophilic surfaces like those of glass or plasma-treated polystyrene promote bacterial twitching, bypassing the requirement for detergents. The implication is that surface properties, such as those of tissues and medical implants, significantly impact the functionality of bacterial T4P as a virulence determinant. This offers valuable insights for developing countermeasures against the colonization and infection by bacterial pathogens of critical importance to human health on a global scale.

Two-Dimensional Materials/Biopolymer-Based Antimicrobial Coatings to Thwart Biofilm Formation on Medical Implants.

Infections associated with medical implants due to bacterial adhesion and biofilm formation are a serious problem, leading to acute health risks to patients by compromising their immune system. Therefore, suppressing biofilm formation on biomedical implants is a challenging task, especially for overcoming the drug resistance of bacterial biofilms. Herein, a synergistic efficient surface coating method was developed to inhibit biofilm formation on a model medical implant by combining the antimicrobial property of trimethyl chitosan (TMC) with either 2D material graphene oxide (GO) or black phosphorus (BP) sheets using layer-by-layer (LbL) self-assembly. The multilayer coatings of TMC/GO and TMC/BP were optimized on the glass surface (a model implant) and characterized by using spectroscopic and microscopy techniques. Next, we investigated the antibiofilm formation properties of the TMC/GO and TMC/BP coatings on glass surfaces against both Gram-negative, Escherichia coli (E. coli), and Gram-positive, Bacillus subtilis (B. subtilis), bacteria. The antibiofilm formation was studied using crystal violet (CV) and live/dead assays. Both the live/dead and the CV assays confirmed that the TMC/2D material (2DM)-coated surfaces prevented biofilm formation much more effectively compared to the uncoated surfaces. Scanning electron microscopy analyses revealed that the bacteria were affected physically by incubating with TMC/2DM-coated surfaces due to membrane perturbation, thereby preventing cell attachment and biofilm formation. Further, BP composite coatings (TMC/BP) showed a much better ability to thwart biofilm formation than GO composite coatings (TMC/GO). Also, multilayer coatings showed superior cytocompatibility with human foreskin fibroblast (HFF). Our results demonstrate that the developed coatings TMC/2DMs could be potential candidates for thwarting biofilm formation on medical implants.

Electrical Conductivity, Thermo-Mechanical Properties, and Cytotoxicity of Poly(3,4-Ethylenedioxythiophene):Poly(Styrene Sulfonate) (PEDOT:PSS)/Sulfonated Polyurethane Blends.

Electrically conductive polymeric materials have recently garnered significant interest from researchers due to their potential applications in the biomedical field, including medical implants, tissue engineering, flexible electronic devices, and biosensors. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is considered the most successful conducting polymer due to its higher electrical conductivity and chemical stability, but it suffers from limited solubility in common organic solvents, poor mechanical properties, and low biocompatibility. An area of tremendous interest is in combining PEDOT:PSS with another polymer to form a blend or composite material in order to access the beneficial properties of both materials. However, the hydrophilic nature of PEDOT:PSS makes it difficult to produce composites with non-polar polymers. In order to overcome these problems, we have specifically designed and synthesized two new sulfonated polyurethanes (PUS) with high sulfonic acid functionality. The two polyurethanes, one water-soluble (PUS1) and one water-insoluble (PUS2), were used to make blends with two commercially available PEDOT:PSS formulations (CleviosTM FET and PH1000). Solvent cast films on glass substrates were made from water-soluble PEDOT:PSS/PUS1 blends while free-standing films of PEDOT:PSS/PUS2 blends were fabricated by compression-moulding. Ethylene glycol was used as conductivity enhancer, which showed an increase in the conductivity by several orders of magnitude in most of the compositions investigated. The highest conductivity of 438 S cm-1 was achieved for the blend with 80 wt% of PEDOT:PSS (PH1000) in PUS1.

Excellent lubricating hydrogels with rapid photothermal sterilization for medical catheters coating

Bacterial infection and tissue damage caused by friction are two major threats to patients’ health in medical catheter implantation. Hydrogels with antibacterial and lubrication effects are competitive candidates for catheter coating materials. Photothermal therapy (PTT) is a highly efficient bactericidal method. Here, a composite hydrogel containing MXene nanosheets and hydrophilic 3-sulfopropyl methacrylate potassium salt (SPMK) is reported, which is synthesized through the one-pot method and heat-initiated polymerization. The hydrogel shows excellent antibacterial performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in 3 min in the air or 20 min in the water environment under near-infrared light (NIR; 808 nm) irradiation. The friction coefficient of the hydrogel is about 0.11, which is 48% lower than that without SPMK. The rapid photothermal sterilization is attributed to the outstanding antibacterial ability and thermal effect of photoactivated MXene. The ultra-low friction is the result of the hydration lubrication mechanism. This study provides a potential strategy for the surface coatings of biomedical catheters, which enables rapid sterilization and extremely low interface resistance between catheters and biological tissues.

Parameters Tailoring on the Deposition of Hydroxyapatite by Pulsed Electrical Discharge.

The creation of strong adhesive layers of hydroxyapatite-based bioceramics (with or without bioinert metals, such as Ta, Ag, and Ti) on biocompatible metallic supports enhances the local biofunctionalization of surfaces. The processing of electroconductive materials using electrical impulse discharges is versatile, enabling precise coating of selected areas with perfectly adherent layers of varying thicknesses. This study aims to quantify the effects of varying the electrical power from the source generating the impulse discharge and the specific processing time per unit area of the cathode (made of titanium alloy) on the relative mass increase of the cathode. The anode comprised a mixture of hydroxyapatite powder and a self-polymerizing electroconductive acrylic resin in a tantalum sheath. The effects of the parameter adjustments on single-layer deposition adherence were quantified using a central composite design to build a second-order orthogonal model. The most significant difference in relative mass was observed with a low-power source (5 W) ensuring the electrical discharge impulse, combined with the longest specified surface treatment time (17.5 s/cm2 on a 4 cm2 surface) for a single layer presenting the largest mass increase of 0.153% of the original mass. This study aimed to enhance the performance of medical implants by optimizing surface biofunctionalization through robust hydroxyapatite-based bioceramic adhesive layers on metallic supports, determining the optimal electrical power and processing time for cathode mass increase during deposition processes, and analyzing parameter adjustments using second-order statistical orthogonal central composite programming, with a focus on single-layer deposition to identify significant differences in relative mass under specific conditions.

Nanofilament organization in highly tough fibers based on lamin proteins

The escalating plastic pollution crisis necessitates sustainable alternatives, and one promising solution involves replacing petroleum-based polymers with fibrous proteins. This study focused on the recombinant production of intracellular fibrous proteins, specifically Caenorhabditis elegans lamin (Ce-lamin). Ce-lamins spontaneously organize within the cell nucleus, forming a network of nanofilaments. This intricate structure serves as an active layer that responds dynamically to mechanical strain and stress. Herein, we investigated the arrangement of nanofilaments into nanofibrils within wet-spun Ce-lamin fibers using alcoholic solutions as coagulants. Our goal was to understand their structural and mechanical properties, particularly in comparison with those produced with solutions containing Ca+2 ions, which typically result in the formation of nanofibrils with a collagen-like pattern. The introduction of ethanol solutions significantly altered this pattern, likely through rearrangement of the nanofilaments. Nevertheless, the resulting fibers exhibited superior toughness and strain, outperforming various synthetic fibers. The significance of the nanofilament structure in enhancing fiber toughness was emphasized through both the secondary structure transition during stretching and the influence of the Q159K point mutation. This study improves our understanding of the structural and mechanical aspects of Ce-lamin fibers, paving the way for the development of eco-friendly and high-quality fibers suitable for various applications, including medical implants and composite materials.

Screening of Lithium Substituted Ag-TiO2 Nanoparticle Coating for Antibiofilm Application.

Bacterial infections and biofilm growth are common mishaps associated with medical devices, and they contribute significantly to ill health and mortality. Removal of bacterial deposition from these devices is a major challenge, resulting in an immediate necessity for developing antibacterial coatings on the surfaces of medical implants. In this context, we developed an innovative coating strategy that can operate at low temperatures (80 °C) and preserve the devices' integrity and functionality. An innovative Ag-TiO2 based coating was developed by ion exchange between silver nitrate (AgNO3) and lithium titanate (Li4Ti5O12) on glass substrates for different periods, ranging from 10 to 60 min. The differently coated samples were tested for their antibacterial and antibiofilm efficacy.

Covalent Grafting of Tanfloc on Titania Nanotube Arrays: An Approach to Mitigate Bacterial Adhesion and Improve the Antibacterial Efficacy of Titanium Implants

AbstractImplanted medical devices often face the challenge of infections, which can compromise their successful integration and use. To address this issue, this study demonstrates the covalent grafting of a tannin‐based antimicrobial biopolymer tanfloc (TAN) onto the titania nanotube arrays (TiNTs) surface to enhance antibacterial properties. Due to its polyphenolic and ionic structural configuration, tanfloc possesses unique properties that enable it to interact with and disrupt bacterial cell walls and membranes. Combining the topographical effect of TiNTs with the inherent antibacterial properties of tanfloc, this approach aims to mitigate bacterial threats on medical implants effectively. The successful attachment of tanfloc on TiNTs is confirmed through X‐ray photoelectron spectroscopy (XPS) and Fourier‐transform infrared spectroscopy (FT‐IR). The antibacterial and antibiofilm efficacy of the tanfloc‐functionalized TiNTs is evaluated against Staphylococcus aureus (Gram‐positive) and Pseudomonas aeruginosa (Gram‐negative) bacteria. The findings suggest that the covalent conjugation of tanfloc onto TiNTs is a promising approach to improve the infection resistance of titanium‐based medical implants, with potential applications in orthopedic, dental, and other biomedical device areas.

Influence of the process parameters on the microstructure and the machinability of additively manufactured Ti-5553 titanium alloy

Additive Manufacturing (AM) technologies, particularly laser powder bed fusion (LPBF), are revolutionising the production of complex geometries and lightweight structures. Furthermore, LPBF allows to tailor the microstructure and resulting properties of metallic materials. This study focuses on titanium alloys, crucial for high-performance applications like aircraft components and medical implants. Although AM enables near-net-shape fabrication, many titanium parts still require machining to meet surface and dimensional standards. Titanium’s challenging machinability is well-documented for cast and wrought alloys, but only less is known about additively manufactured variants. In this work, the machinability of an additively manufactured Ti-5Al-5V-5Mo-3Cr alloy (Ti-5553) is investigated, focusing on chip formation, cutting forces, and tool wear across different LPBF process parameters. Four LPBF parameter sets were validated, and results were compared to conventional wrought sample. The findings reveal significant variations in machinability linked to LPBF parameters. Specifically, the highest tool loads and wear were observed for samples produced with the highest energy density of EV = 37.0 J/mm3, likely due to α-phase precipitation. In contrast, samples with lower energy densities (<29.1 J/mm3) exhibited up to 100% longer tool life. Concluding, this study highlights how the machinability of Ti-based components can be significantly influenced by the LPBF processing parameters.

Thickness-extensible higher order plate theory with enforced C1 continuity for the analysis of PEEK medical implants

Plate-like structures had been thoroughly studied in literature over years to reduce the computational space from 3D to 2D. Many of these theories suffer either from satisfying the free traction condition or thickness extensibility in addition to the consistency of transverse shear strain energy. This work presents a higher order shear deformation thickness-extensible plate theory (eHSDT) for the analysis of plates. The proposed eHSDT satisfies the condition of free traction as other theories do but it also satisfies the condition of consistency of transverse shear strain energy which is neglected by many theories in the area of plates and shells. The implementation of the proposed theory in displacement-based finite element procedure requires continuity of derivatives across elements. This necessary condition was achieved using the penalty enforcement method for derivative-based nodal degrees of freedom across the standard 9-nodes Lagrange element. The theory was tested for elastic bending deformation of Polyether-ether-ketone (PEEK) which is one of the basic materials for medical implants. The theory showed good accuracy compared to experimental data of the three-points bending test. The present eHSDT was also tested for different conditions with a wide range of aspects ratios (thin to thick plates) and different boundary conditions. The accuracy of the proposed eHSDT was verified against exact solutions for these conditions which showed the advantage over other approaches and commercial finite element packages.

Advanced Nanotechnological Approaches for Biofilm Prevention and Control

Biofilm-associated infections present a significant challenge in modern medicine, primarily due to their resilience and resistance to conventional treatments. These infections occur when bacteria form biofilms, protective layers formed by bacterial communities, which are notoriously resistant to traditional antibiotics on surfaces such as medical implants and biological surfaces, making eradication with standard antibiotics difficult. This resilience leads to persistent infections, imposing a substantial economic burden on healthcare systems. The urgency to find alternative treatments is critical as current methods are insufficient and costly. Innovative approaches, such as nanotechnology-based therapies, offer promising alternatives by targeting biofilms more effectively and reducing the need for invasive procedures. Nanocarriers hold significant promise in the fight against biofilm-associated infections. Nanocarriers can penetrate biofilms more effectively than conventional treatments, delivering higher concentrations of antibiotics or other antimicrobial agents precisely where they are needed. This targeted approach not only enhances the efficacy of treatments but also minimizes potential side effects. The development of nanocarrier-based therapies is crucial for overcoming the limitations of current treatments and ultimately improving patient outcomes and reducing the economic burden of biofilm-associated infections on healthcare systems. In this review, nanotechnology-based systems, their characteristics, limitations, and potential benefits are explored to address biofilms-related infections. Additionally, biofilm evaluation models and the tests necessary for the preclinical validation of these nanosystems to facilitate their clinical application are addressed.

3D printable gelatin/nisin biomaterial inks for antimicrobial tissue engineering applications.

Modern regenerative medicine approaches can rely on the fabrication of personalised medical devices and implants; however, many of these can fail due to infections, requiring antibiotics and revision surgeries. Given the rise in multidrug resistant bacteria, developing implants with antimicrobial activity without the use of traditional antibiotics is crucial for successful implant integration and improving patient outcomes. 3D printed gelatin-based implants have a broad range of applications in regenerative medicine due to their biocompatibility, ease of modification and degradability. In this paper, we report on the development of gelatin biomaterial inks loaded with the antimicrobial peptide, nisin, for extrusion-based 3D printing to produce scaffolds with controlled porosity, high shape fidelity, and structural stability. Rheological properties were comprehensively studied to develop inks that had shear thinning behaviour and viscoelastic properties to ensure optimal printability and extrudability, and enable precise deposition and structural integrity during 3D printing. The 3D printed scaffolds fabricated from the gelatin/nisin inks demonstrated excellent antimicrobial efficacy (complete kill) against Gram positive bacteria methicillin-resistant Staphylococcus aureus (MRSA). Overall, this ink's high printability and antimicrobial efficacy with the model antimicrobial peptide, nisin, offers the potential to develop customisable regenerative medicine implants that can effectively combat infection without contributing to the development of multidrug resistant bacteria.

Advanced 3D Micro‐Electrodes for On‐Chip Zinc‐Ion Micro‐Batteries

AbstractThe development of high‐performance planar micro‐batteries featuring safer, cost‐effective systems is crucial for powering smart devices such as medical implants, micro‐robots, micro‐sensors, and the Internet of Things (IoT). However, current on‐chip micro‐batteries suffer from limited energy density within constrained device footprints due to challenges in effectively loading high‐capacity active materials onto micro‐electrodes. Innovative designs for advanced micro‐electrodes are needed for on‐chip micro‐batteries. This work introduces advanced, highly porous 3D gold (Au) scaffold‐based interdigitated electrodes (IDEs) as current collectors, which enable effective loading of active materials (Zn and polyaniline) without compromising overall conductivity and significantly increase active mass loading. These 3D Au scaffold‐based micro‐batteries (3D P‐ZIMB) offer substantially higher energy storage performance (≈135% enhancement) compared to conventional micro‐batteries (C‐ZIMB) when materials loaded onto flat Au IDEs. Furthermore, the 3D P‐ZIMB demonstrates higher areal capacities (≈35 µAh cm−2) and areal energy (≈31.05 µWh cm−2) than most high‐performance on‐chip micro‐batteries, and it delivers a much higher areal power (≈3584.35 µW cm−2) than high‐performance on‐chip micro‐supercapacitors. In‐depth postmortem investigations reveal that the 3D P‐ZIMB avoids issues like material peeling, sluggish electrolyte ion diffusion, and dendrite formation on the anode, while maintaining identical material morphologies and structural characteristics. Therefore, this study presents a smart strategy to enhance the electrochemical performance of planar micro‐batteries and advance the field of on‐chip micro‐battery research.

Using a Bacterial Protein to Selectively Target Bacterial Biofilms: Treatment of S. epidermidis Biofilms with Targeted Photothermal Gold Nanoparticles.

Biofilm-related infections are associated with high mortality and morbidity, combined with increased treatment costs. Traditional antibiotics are becoming less effective due to the emergence of drug-resistant bacterial strains. The need to treat biofilms on medical implants is particularly acute, and one persistent challenge is selectively directing nanoparticles to the biofilm site. Here, we present a protein-based functionalization strategy that targets the extracellular matrix of biofilms. The protein, derived from the extracellular Staphylococcus epidermidis autolysin, directs nanoparticles to S. epidermidis cell wall components, which are not expected to be present in mammalian tissues. This functionalization is applied to a gold nanoparticle (AuNP) core, along with elastin-like polypeptides (ELPs), which generate a robust photothermal response. In addition to biofilm targeting, the particles exhibit low protein binding, and the photothermal conversion can be modulated by changing the ELP transition temperature. These functionalized AuNPs strongly interact with biofilms under static and flow conditions but exhibit weak interactions with serum-coated surfaces. Near-infrared laser irradiation resulted in a 10,000-fold improvement in killing efficiency compared to untreated controls (p < 0.0001). The targeting strategy utilized here represents a versatile approach to targeting drug-resistant infections and could be readily expanded to other anti-biofilm nanoparticle platforms.

The Application Progress of Nonthermal Plasma Technology in the Modification of Bone Implant Materials.

With the accelerating trend of global aging, bone damage caused by orthopedic diseases, such as osteoporosis and fractures, has become a shared international event. Traffic accidents, high-altitude falls, and other incidents are increasing daily, and the demand for bone implant treatment is also growing. Although extensive research has been conducted in the past decade to develop medical implants for bone regeneration and healing of body tissues, due to their low biocompatibility, weak bone integration ability, and high postoperative infection rates, pure titanium alloys, such as Ti-6A1-4V and Ti-6A1-7Nb, although widely used in clinical practice, have poor induction of phosphate deposition and wear resistance, and Ti-Zr alloy exhibits a lack of mechanical stability and processing complexity. In contrast, the Ti-Ni alloy exhibits toxicity and low thermal conductivity. Nonthermal plasma (NTP) has aroused widespread interest in synthesizing and modifying implanted materials. More and more researchers are using plasma to modify target catalysts such as changing the dispersion of active sites, adjusting electronic properties, enhancing metal carrier interactions, and changing their morphology. NTP provides an alternative option for catalysts in the modification processes of oxidation, reduction, etching, coating, and doping, especially for materials that cannot tolerate thermodynamic or thermosensitive reactions. This review will focus on applying NTP technology in bone implant material modification and analyze the overall performance of three common types of bone implant materials, including metals, ceramics, and polymers. The challenges faced by NTP material modification are also discussed.

A discrete CMUT self-biasing circuit towards implanted devices application

Wireless power transfer is an essential feature of biomedical engineering. It reduces the need for energy storage devices in medical implants. To recharge a body implanted battery, a convenient way is to transmit ultrasounds through the skin to a connected ultrasonic transducer. Lead-less, System-on-Chip compatible (SoC) and wideband, Capacitive Micromachined Ultrasonic Transducers (CMUT) are competitive with piezoelectric based technologies. However, their need for a high bias voltage is an obstacle to their use in implanted medical devices (IMDs). The voltage source required must meet precise specifications, such as reliability and volume, which the research community intends to respect. To meet this challenge, this work proposes an electronic circuit that allows a CMUT device to self-bias from a very low initial energy input. After presenting the electronic architecture and its main features, simulation and experimental results validate the solution’s working principle and operating points. With an electronic circuit made up of discrete components, a bias voltage of 60 V is built up from an implanted battery voltage of 2.2 V and an incident pressure of 120 kPa in water.

Tough, Slippery, and Low-Permeability Multilayer Hydrogels Modified by Anisotropic Fiber Membrane for Soft Tissue Replacement.

Hydrogels with sustained lubrication, high load-bearing capacity, and wear resistance are essential for applications in soft tissue replacements and soft material devices. Traditional tough or lubricious hydrogels fail to balance the lubrication and load-bearing functions. Inspired by the gradient-ordered multilayer structures of natural tissues (such as cartilage and ligaments), a tough, smooth, low-permeability, and low-friction anisotropic layered electrospun fiber membrane-reinforced hydrogel was developed using electrospinning and annealing recrystallization. This hydrogel features a stratified porous network structure of varying sizes with tightly bonded interfaces, achieving an interfacial bonding toughness of 1.6 × 103 J/m2. The anisotropic fiber membranes, mimicking the orderly fiber structures within soft tissues, significantly enhance the mechanical properties of the hydrogel with a fracture strength of 20.95 MPa, a Young's modulus of 29.64 MPa, and a tear toughness of 37.94 kJ/m2 and reduce its permeability coefficient (6.1 × 10-17 m4 N-1 s-1). Meanwhile, the hydrogel demonstrates excellent solid-liquid phase load-bearing characteristics, which can markedly improve the tribological performance. Under a contact load of 4.1 MPa, the anisotropic fiber membrane-reinforced hydrogel achieves a friction coefficient of 0.036, a 219% reduction compared with pure hydrogels. Thus, the superior load-bearing and lubricating properties of this layered hydrogel underscore its potential applications in soft tissue replacements, medical implants, and other biomedical devices.

Active and passive electronic interfaces adapted to a capacitive micromachined ultrasonic transducer (CMUT) used in acoustic energy transfer

Wireless power transfer is a key feature in the field of biomedical engineering. It allows a reduction of the energy storage devices in medical implants. An efficient way to safely transfer energy to medical implants is to convey ultrasounds through the body to a Capacitive Micromachined Ultrasonic Transducer (CMUT). For an application of ultrasonic energy transfer through skin, the present work compares the efficiency of two different electronic architectures to receive energy from an array of CMUT. The well known Synchronous Switch Harvesting on Inductor (SSHI) is compared in simulation to a simple impedance matching. Indeed, for an ultrasonic energy transfer, the high excitation frequency (1–8 MHz) allows the use of an inductor matching the CMUT’s clamped capacitor. The simplicity of an impedance matching circuit, its low volume and its efficiency makes it the best choice for an efficient energy transfer process to the targeted load. The CMUT model used in the simulations is a mason’s model which component values are extracted from the impedance measurement of a real device. In the end, the impedance matching is experimentally tested on this same device and compared to the simulation. A maximum 4,5 mW power is transferred to an optimal load for an input ultrasound pressure of 90 kPa.

Application of Medical Implants for Public Health Monitoring and Treatment

The World Health Organisation (WHO) reports that diabetes affects roughly 180 million people worldwide and that cardiovascular illnesses account for nearly 30% of all fatalities worldwide. Applications involving radio frequency (RF) or microwave technology are crucial to medical diagnosis and illness prevention. The most recent developments in the field of implantable medical devices (IMDs), such as biomedical telemetry, allow biosignals to be monitored remotely via wireless communication technology. Providing correct information to the external monitoring station is the primary function of the health maintenance monitoring scheme. Because wireless communication lessens the invasiveness of electromagnetic (EM) medical equipment, it is extremely helpful in improving patient comfort during treatment. The first swallowable pills with sensing capabilities and the introduction of pacemakers in the early 1960s both demonstrated the significance of implantable medical devices (IMDs), which enable disease monitoring and therapy. Using IMDs with wireless connection has allowed for the monitoring of both system performance and patient status. IMDs have been widely employed in healthcare systems to gather real-time signals from biosensors or preprocessed physiological bio-signals for early disease identification, improving treatment quality and promoting healthy living.

Rheological impact of viscous fluid in the core region of heated curved pipe surrounded by Casson rheological fluid

The immiscible fluids can help design more efficient systems for drug delivery and understanding the blood flow through diseased arteries. It can also have implications for the design of flow control devices or medical implants that involve curved geometries. Therefore, the current article scrutinizes the characteristics of heat transfer on the flow of two immiscible Casson and Newtonian fluids through a curved pipe induced due to a pressure gradient in an axial direction. The pipe is divided into two distinct regions: namely, (i) Region 1 (core) is filled with Newtonian fluid while (ii) Region 2 (peripheral) is filled with non-Newtonian Casson fluid. The complex curvilinear coordinates called toroidal coordinates are used to form a mathematical model for the present problem. Equations governing the flow are considered without ignoring any curvature ratio terms and are solved analytically by considering the perturbation series. The continuity of velocities and shear stresses at the fluid-fluid interface is taken into account along with no-slip, symmetric, and regularity conditions while solving the two-fluid flow problem under consideration. The effect of various fluid parameters such as curvature ratio, Casson fluid parameter, Reynolds number, viscosity ratio, density ratio, Eckert number, and conductivity ratio on the axial velocity and temperature is studied through 2-dimensional graphs and contour plots. In addition, the volumetric flow rate and shear stress are also presented to evaluate the effects of various key parameters. The results show that the axial velocity of immiscible fluids flow increases with an increase in the values of the viscosity ratio parameter and the fluid temperature is decreased by increasing the conductivity ratio parameter.